Background: This study examined how the frequency of in-person, telephone, text-based communication, and video interactions with non-cohabiting family and friends relates to loneliness among older adults in Japan. Methods: We analyzed data from 6,786 adults aged ≥65 in the 2024 Japan COVID-19 and Society Internet Survey (JACSIS) study. Interaction frequency with non-cohabiting family and friends was categorized into none (reference), monthly, and weekly or more. Loneliness was measured using the 3-item UCLA Loneliness Scale and dichotomized at ≥4, indicating loneliness; a ≥7 cut-off was used in sensitivity analyses. Logistic regression models adjusted for sociodemographic, lifestyle, and health-related factors. Results: For family, significant associations with lower loneliness were observed only at weekly frequencies—in-person (adjusted odds ratio [aOR]=0.764, 95% confidence interval [CI] 0.664–0.879), text (aOR=0.747, 95% CI 0.659–0.846), and telephone (aOR=0.624, 95% CI 0.543–0.718), whereas for friends, significant associations were observed at monthly frequencies—in-person (aOR=0.621, 95% CI 0.549–0.701), text (aOR=0.881, 95% CI 0.778–0.997), and telephone (aOR=0.734, 95% CI 0.659–0.819). Video calls were associated with lower odds of severe loneliness (score ≥7) in sensitivity analyses—weekly calls with family (aOR=0.736, 95% CI 0.547–0.991) and monthly calls with friends (aOR=0.656, 95% CI 0.470–0.917). Conclusion Interactions with friends show associations with lower levels of loneliness at lower frequencies than family contact. While text and phone calls are broadly associated with reduced loneliness, video calls showed an association specifically with a lower prevalence of severe loneliness, underscoring the potential for tailored communication strategies.

BACKGROUND: Studies have shown that married couples often share similar lifestyles, as well as lifestyle-associated conditions such as diabetes, hypertension, and hyperlipidemia. This study aims to prospectively investigate the association between an individual's development of a non-communicable disease and the subsequent development of the same condition in their spouse. METHODS: This population-based cohort study utilized 12 waves of annual prospective surveys from 2005 onwards in Japan, with a discrete-time design. A total of 9,417 middle-aged couples (18,834 participants; discrete-time observations = 118,876) were included. Each participant whose spouse had developed one of six conditions was propensity score-matched with five controls whose spouses had not been diagnosed with the condition: diabetes [n = 1374 vs n = 6870], hypertension [n = 2657 vs n = 13285], hypercholesterolemia [n = 3321 vs n = 16605], stroke [n = 567 vs n = 2835], coronary heart disease (CHD) [n = 1093 vs n = 5465] or cancer [n = 923 vs n = 4615]. Using conditional logistic regression, we assessed participants' development of the same condition within three years following their spouse's diagnosis. RESULTS: Participants whose spouses had developed diabetes, hypertension, hypercholesterolemia, or CHD were more likely to develop the same condition within three years. The odds ratios (ORs) and 95% confidence intervals (CIs) were: 1.96 (1.53-2.50), 1.20 (1.06-1.36), 1.63 (1.47-1.81) and 1.43 (1.05-1.95), respectively. No significant associations were observed in stroke [1.69 (0.80-3.58)] or cancer [1.08 (0.75-1.54)]. CONCLUSION Spouses of individuals recently diagnosed with certain metabolic conditions are at a higher risk of developing those conditions themselves. These findings may provide valuable guidance for targeting and personalizing chronic disease screening and prevention efforts.
Humans ; Spouses/statistics & numerical data* ; Male ; Female ; Middle Aged ; Aged ; Japan/epidemiology* ; Longitudinal Studies ; Noncommunicable Diseases/epidemiology* ; Prospective Studies ; Neoplasms/epidemiology* ; Diabetes Mellitus/epidemiology* ; Risk Factors ; Aged, 80 and over ; Adult ; Hypertension/epidemiology*

BACKGROUND: Although the global COVID-19 mortality rate is decreasing, COVID-19 remains an infectious disease with a high mortality rate, especially in older adults and individuals with comorbidities. In Japan, mask-wearing has been left to individual discretion since March 13, 2023, but remains a key protective measure. This study aimed to identify factors influencing individual mask-wearing behavior in post COVID-19 era, with a focus on risk factors for severe COVID-19. METHODS: Data from 33,000 participants, obtained from the Japan COVID-19 and Society Internet Survey 2023, were used, which was conducted from September 25 to November 17, 2023. Participants were randomly selected from approximately 2.2 million panelists from a nationwide Japanese Internet research company, with sampling adjusted by age, sex, and living area to match the population distribution in Japan. The association between wearing a mask and risk factors for severe COVID-19 (age, sex, smoking, COVID-19 vaccination, history of COVID-19, body mass index (BMI), and comorbid conditions) was evaluated using univariate and multivariate analyses. RESULTS: In total, 28,481 individuals were included, of whom 18,371 (64.5%) answered that they wore masks. After adjusting for confounders, older age (adjusted relative risk [RR], 1.50; 95% confidence interval [CI], 1.45-1.55 for "75-83" years), no history of COVID-19 (adjusted RR, 1.06; 95% CI, 1.04-1.08), low BMI (adjusted RR, 1.04; 95% CI, 1.02-1.07), and increased number of comorbid conditions (adjusted RR, 1.11; 95% CI, 1.05-1.18 for three or more) were significant positive factors for wearing a mask. In contrast, men (adjusted RR, 0.89; 95% CI, 0.87-0.90), no COVID-19 vaccination (adjusted RR, 0.78; 95% CI, 0.76-0.81), and current smoking history (adjusted RR, 0.96; 95% CI, 0.93-0.99) were significant negative factors. CONCLUSION We demonstrated that mask-wearing behavior differed based on individual risk factors for severe COVID-19, with some risk factors negatively influencing mask use in Japan. It may be necessary to recommend mask-wearing for these individuals, especially during situations such as COVID-19 epidemic season or the onset of epidemics, considering individual mask-wearing behavior.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; COVID-19/psychology* ; Japan/epidemiology* ; Masks/statistics & numerical data* ; Risk Factors ; Surveys and Questionnaires ; East Asian People

BACKGROUND: Heated tobacco products (HTPs) are widely used in Japan, following cigarettes, but their health effects remain unclear. HTPs are often considered a less harmful alternative to cigarettes and are commonly used by adults with asthma, even though smoking is one of the most obvious and treatable factors in asthma. We aimed to elucidate the association between HTP use and asthma symptoms in adults with asthma. METHODS: A total of 3,787 individuals with asthma were extracted from the data in the Japan COVID-19 and Society Internet Survey 2023, an ongoing longitudinal internet-based cohort study conducted by a nationwide internet research company in Japan. They were categorized into three groups (never, past, and current smokers) based on cigarette use. The association between HTP use and worsening of asthma symptoms within the previous 2 months in each group was analyzed using univariate and multivariate logistic regression analyses. Both exposure and outcomes were assessed by self-reporting. RESULTS: Among the participants, 2,470 (65.2%) were never smokers, 845 (22.3%) were past smokers, and 472 (12.5%) were current smokers. Overall, the proportion of HTP users was 429 (11.3%), and worsened asthma symptoms were observed in 400 (10.6%) individuals. The total proportion of HTP users and worsened asthma symptoms was 70 (2.8%) and 259 (10.5%) among never smokers, 180 (21.3%) and 72 (8.5%) among past smokers, and 179 (37.9%) and 69 (14.6%) among current smokers. After adjusting for confounders, the odds ratio (OR) was 3.25 (95% confidence interval [CI] 1.86-5.68, p < 0.001), 1.47 (95% CI 0.93-2.34, p = 0.1), and 2.23 (95% CI 1.46-3.43, p < 0.001) for never, past, and current cigarette smokers with HTP use, respectively, where never smokers without HTP use were set as the standard. CONCLUSION The use of HTPs, not only cigarette smoking, was associated with worsening of asthma symptoms in adults with asthma. Therefore, people need to understand the harmful effects of HTPs on asthma symptoms.
Humans ; Japan/epidemiology* ; Asthma/etiology* ; Male ; Female ; Middle Aged ; Adult ; Aged ; Tobacco Products/adverse effects* ; Internet ; Surveys and Questionnaires ; Young Adult ; Hot Temperature ; Longitudinal Studies

BACKGROUND: Heated tobacco product (HTP) use has increased substantially between 2016 and 2017 in Japan. This study aims to clarify how HTP use (IQOS, Ploom, and glo) spread across the different combustible cigarette smoking statuses during 2015-16 and 2017-18 in Japan. METHODS: We compared the two periods of (i) 2015 to 2016 (N = 5,366) and (ii) 2017 to 2018 (N = 3,422) from a longitudinal study randomly sampling members from the Japan "Society and New Tobacco" Internet Survey (JASTIS). Multivariable logistic regression models for current HTP use in the previous 30 days by combustible cigarette smoking status in the previous year were used adjusting for socio-demographic factors. RESULTS: HTP use increased by 10 times in the 2017-18 cohort compared with the 2015-16 cohort according to the adjusted odds ratio (95% confidence interval) for current HTP use as 10.2 (7.03-14.8). According to smoking status, significantly higher adjusted ORs (95% CIs) of current HTP use for the after period were observed: 2.60 (1.37-4.94) for never smokers, 7.82 (3.64-16.8) for former smokers, 21.1 (5.73-77.9) for current smokers with intention to quit, and 17.0 (9.58-30.3) for current smokers without intention to quit. CONCLUSION During 2015 to 2018 in Japan, HTP use dramatically increased in all subgroups except for never smokers.
Humans ; Japan/epidemiology* ; Longitudinal Studies ; Tobacco Products ; Tobacco ; Cigarette Smoking ; Surveys and Questionnaires

BACKGROUND: Before the COVID-19 vaccine became available, many Japanese people were undecided about whether or not to receive them. Their decisions were keys to achieving herd immunity. The impact of the type of information source on the COVID-19 vaccine uptake decision-making process remains unclear. We aimed to investigate the association between information source usage on COVID-19 and subsequent vaccine uptake status among those who have yet to decide whether to receive vaccines from non-prioritized people for vaccination. METHODS: Prospective cohort online self-administered surveys were conducted in February 2021 (T1), before the start of the mass vaccination program, and September-October 2021 (T2), when the vaccines were available to all citizens. The survey's target population was registered monitors of an Internet research company. Participants who answered "I want to get vaccinated after waiting to see how it goes." at T1 were eligible for analysis. The outcome variable was the COVID-19 vaccine uptake status in T2, and the predictors were 20 types of information sources, categorized based on people (family members, etc.), institutions (governments, etc.), or media (TV news, etc.). Adjusted odds ratio and 95% confidence intervals were estimated using logistic regression adjusted for possible confounders. RESULTS: The 5,139 respondents, mean age and standard deviation was 42.8 ± 12.5, 55.7% female, were eligible for analysis. 85.7% completed vaccination (including reserved/intended people) in T2. In the multivariate logistic analysis, odds ratios (95% confidence interval) for vaccine uptake were 1.49 (1.18-1.89) for workplaces/schools, 1.81 (1.33-2.47) for LINE, 0.69 (0.55-0.86) for Internet news and 0.62 (0.48-0.82) for video sharing sites. CONCLUSIONS The type of information source usage played an important role in the decision to vaccinate against COVID-19. Although caution is needed in interpreting the results, obtaining information from workplaces/schools and LINE was influential in promoting immunization.
Humans ; Female ; Male ; Information Sources ; COVID-19 Vaccines ; Prospective Studies ; Intention ; Japan ; COVID-19/prevention & control* ; Vaccination

The purpose of this study was to confirm the causal structure model of muscle, motor and living functions utilizing structural equation modeling (SEM) . As subjects, 103 community-dwelling older men and women, aged 65.7±6.9years of age, participated in the study to measure muscle cross-sectional area, maximum voluntary contractions, muscle power, 4 physical performance tests, and 16 questionnaires regarding ability of activities of daily living. The causal structure model of muscle, motor and living functions was hypothesized to be a hierarchical causal structure. The causal structure model of muscle function was hypothesized to be a hierarchical causal structure consisting of 3 sub-domains of muscle mass, muscle strength, and muscle power. Data analysis procedures were as follows : a) testing of construct validity of muscle function variables using confirmatory factor analysis (CFA) in SEM ; b) testing of causal structure using SEM ; c) testing of factor invariance using multi-group analysis for gender. The highest goodness of fit indices was obtained in the causal structure model of muscle, motor and living functions (NFI= .928, CFI= .978, RMSEA =.061) . The causal coefficient of muscle function to motor function was .98 (p<.05), followed by.34 for motor function to living function. From the results of multi-group analysis, the measurement invariance model indicated the highest goodness of fit indices (TLI=.968, CFI .977) . It was concluded that the hierarchical causal relation was among muscle, motor and living functions, and in which muscle function was consisted of 3 sub-domains.

The purpose of this study was to confirm the reliability and validity of a physical fitness questionnaire (PFQ) with self-rating for elderly people applying structural equation modeling (SEM) . As subjects, 105 community-dwelling older men and women aged 67.1±6.1 years participated in the study to measure 13 PFQ items and 13 performance tests. The data analysis procedures were as follows : a) testing reliability of PFQ ; b) testing of construct validity of PFQ using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) ; c) testing of criterion-related validity of PFQ to the performance tests using SEM ; d) testing of correlations of the PFQ to walking ability using SEM. Cronbaeh's alpha coefficient for consistency reliability of the PFQ was .83. Four common factors of muscle strength-power, endurance, coordination, and flexibility were extracted in EFA. The high and enough goodness of fit indices were obtained in the confirmatory factor structure model, and in each sub-domain of criterion-related validity to performance tests and correlation to walking ability models. The criterion-related validity coefficient of muscle strength and power was .77, followed by .66 for endurance, .59 for coordination and .82 for flexibility. The correlation coefficient of muscle strength and power to walking ability was -.51, followed by -.58 for coordination, - .43 for endurance and - . 28 for flexibility. These results indicated that the PFQ consisting of 13 items and 4 sub-domains satisfied reliability and construct validity although criterion related validity to performance tests was insufficient. It was concluded that the PFQ is of useful for physical fitness checking of elderly people.

The purpose of this study was to confirm the causal effect model of strength on walking ability development as a result of exercise participation among elderly people in a community, utilizing the latent curve model (LCM) in structural equation modeling (SEM) . Twenty-six male and 57 female subjects, 83 in total, aged 67.8±5.7, 63.9±7.1 and 65.1±6.9 in a pooled sample participated in the exercise program which lasted for two years. Grip strength and sit-ups used in the Japan Fitness Test were measured for muscular strength, 10-m hurdle walk and 6-min walk for walking ability, and the fitness test score for physical ability. The data analysis procedures were as follows : a) analysis of test-retest reliability and construct validity of measurement items, b) analysis of causal structure model of aging, muscular strength and walking ability, c) analysis of variance for repeated measurement of walking performance by sex, age and year, d) analysis of LCM for walking performance development. The highest goodness-of-fit indices of SEM were obtained in the LCM of 10-m hurdle walk performance development (GFI=0.989, AGFI=0.920, CFI=0.998, RMSEA=0.038) . The path coefficient of sit-ups at pre-test effect on the intercept of 10-m hurdle walk performance development was significant (p<0.05) . The path coefficients of age to intercept and slope of 10-m hurdle walk development were also significant (p<0.05) . It was concluded that walking ability development through participation in exercise age and strength level was more effective for maintaining walking ability in older age.